Smooth muscle electromyography of the urinary bladder.
To elucidate smooth muscle activity of the urinary bladder, we utilized an optimized animal model and a specially developed, computer-aided data acquisition and analysis system for bioelectrical signals. Twenty-five Wistar rats were pharmacologically paralyzed and artificially respirated. The urinary bladder was exposed by a suprapubic midabdominal incision, and both ureters were ligated to prevent physiological filling of the bladder. The bladder was initially emptied by slight manual pressure and was then filled via a transurethral catheter in 0.1-ml steps to a maximum of 0.45 ml with physiological saline. A custom-made, gold-plated needle electrode was tangentially guided by a micromanipulator to the smooth muscle of the bladder dome, and the recordings commenced. Furthermore, smooth muscle EMG recordings of the bladder were performed after pharmaco-stimulation of the detrusor with carbachol. Initial results demonstrate that, with the animal model presented here, it is possible to record reproducible and almost artifact-free smooth muscle activity from the urinary bladder. All experiments displayed a stochastic distribution of similar electrical events, increasing in appearance and amplitude with increased bladder volume and after pharmacostimulation with carbachol. Two-dimensional power spectrum analysis revealed a main signal frequency below 1 Hz.
Scheepe
J R
JR
Department of Urology, Klinikum Mannheim of the University of Heidelberg, Germany.
Wipfler
G
G
Schumacher
S
S
Bross
S
S
Zendler
S
S
Jünemann
K P
KP
Alken
P
P
D000818:Animals; D002217:Carbachol; D004576:Electromyography; D001330:Electronic Data Processing; D005260:Female; D005583:Fourier Analysis; D008839:Microelectrodes; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000502:physiology*; D010277:Parasympathomimetics; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013268:Stimulation, Chemical; D001743:Urinary Bladder / Q000502:physiology*
D010277:Parasympathomimetics; D002217:Carbachol